DIY bio pellet help (what do ya think, complete?)

Discussion in 'Filters, Pumps, etc..' started by diverdan, May 9, 2013.

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  1. ingtar_shinowa

    ingtar_shinowa Giant Squid

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    Are you still using a reducer on the end of the inlet pipe?
     
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  3. Powerman

    Powerman Giant Squid

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    As far as tumble.... yes, you want a gentle tumble. You want to slough off bacteria, you do not want to "scrub" them off entirely. Even if you have good flow through the pellets, if they are not moving, you don't know that. And if you channel flow through them and allow dead spots, yes, it is bad. So all the pellets moving is what you want. Just so you know you have flow through all of them.

    With your cone, you will always have that "scrubbing" velocity at the bottom. That is the nature of the design. If you can see the rest of the pellets "turning over", then at least you know it is moving. Every now and then, they will clump up and you will sort of have to blast them to get them moving again.

    The wider you make your reactor, the more flow you will need to get them all moving... but you don't, so you resorted to a device to speed flow. And we are not making it smaller.

    Here is something easy you could try.... The baffle plate you have the pellets sitting on is perforated... which makes perfect sense, but that is not helping. You could use a solid plate, but make it smaller than the reactor diameter. So flow goes up the sides of the reactor... what will happen is you will turn beads over in a circular motion from outside to inside... in theory. ;D (think of it as a conveyor instead of a fluidized bed).

    If you got that right, velocity would be around the whole diameter. The potential downfall would be it would not rotate all the stock and the bottom inside beads would not move.

    The bottom line is that if you want a fluidized bed with the reactor you have, then you need to diffuse the flow... smaller holes in the perforated plate. The water flow to move evenly up the reactor... and a pump big enough to flow enough water to keep the beads fluid.

    If you do not have a big enough pump to do that with the reactor body you have... then yes, you need some sort of "nozzle" to move them... like you came up with the cone...which is actually a good idea.... Have you thought of moving the pipe up a little in the cone instead of less flow, that would "open" the nozzle.
     
  4. Powerman

    Powerman Giant Squid

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  5. jimmy_beaner

    jimmy_beaner Teardrop Maxima Clam

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    But notice the shallow angle of their cone. They don't want that torrent of water near the inlet, which is why they deflect most of it with the shallow angle.
     
  6. diverdan

    diverdan Bangghai Cardinal

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    Wow that have me a lot to think about.
    Yes I can put more holes in the tube.
    No, I'm not using the reducer anymore.
    There are so many things to try to get this right. I will turn down the flow when I get off work and is that does t work then I'll try a diffuser plate. If that doesn't work that I will try to make the tube longer and use a diffuser plate and then if that doesn't work..... I don't know.
    I really appreciate the help and all the ideas.
     
  7. jimmy_beaner

    jimmy_beaner Teardrop Maxima Clam

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    Would it be possible to flatten out the cone near the apex of it? Make it more of a "bowl" design? Or perhaps make a few smaller holes in the tube before it reaches the bottom so some of the flow is distributed before it exits? Which would reduce the flow near the bottom but also encourage movement toward the top, which is where it seems there is a bit less movement?
     
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  9. Powerman

    Powerman Giant Squid

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    Yes... that's R&D for you... keep going till it's right. they probably tried several.

    the angle is shallower, but the other cone also directs and diffuses flow all the way around. So I bet the cone can only be so steep, but I also bet that the little cone at the bottom of the supply tube does a good job of giving more range.

    DD, if you do not have your cone perfectly round, then flow will shoot where ever it is easiest. A second cone might calm that down. I would think with what you have right now, it would be easiest to try the RO design first... if nothing else I bet it gets you really close to what you want.
     
  10. Powerman

    Powerman Giant Squid

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    I'm not so sure you want to do that. Use the flow you have. Putting holes in the tube will just give you undirected flow. We are talking the supply tube right?
     
  11. diverdan

    diverdan Bangghai Cardinal

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    Alright, such great advise. I will try the RO cone. If that doesn't work then I will make the cone shallower and more of a bowl. It's almost there. Thanks for the help again. Very much appreciated!
     
  12. Powerman

    Powerman Giant Squid

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    You know, actually... I bet a flat plate would work too. Much easier to do. What you would have to do is start from where you are at. And just put a plate at the bottom to get rid of that swirl at the bottom of the cone.

    It would direct everything out in 360. You do not want it so close to the end of the supply tube to restrict flow. If that is still too much, then just throttle the pump down a tad. That should be perfect... get the tumble you want, and have a little pump left over to goose it from time to time if needed.

    I used a maxijet 900 on mine, but much smaller tube in a BRS media reactor. You might have to go up to a 1200 (295gph/ $25) to get enough flow like you want. How much pellets do you want to run... a liter?